Ethanol free gas

[F Spider]

Finally there is a gas station in our area that has ethanol free gas. The only problem is that it is "only" 91 octane (premium) gas. US method is different, so I think it is close to 95 octane euro gas.

First measured gas consumption seems to be 8% better, but maybe I used a bit less because of the roads I took. I'll keep an eye on it.

Sidebar would be, that for the first time, my fuel gauge is accurate

I will follow up with more data. Anybody think that 91 octane is bad?

[F Spider]

With some longer distances on this full tank, I got 50 more miles than normal. This is 24MPG, or 1:10. The S2000 has that mileage

The 8% fuel savings with normal driving for Ethanol free gas seems real....

[F Spider]

Filling up...

[mrobin33]

Not legal in NJ else I'd be tempted to try it. The engine management should adjust for lower octane in theory, and retard the ignition to avoid 'pinking' or pre-detonation. You'd notice maybe a little loss of performance, maybe.

BUT sometimes (often) software engineers get it wrong - I had a modern Camaro a few years ago that would select a different engine map if it detected low octane fuel. Trouble was that it forgot to revert to the higher performance map if you put higher octane fuel in later on. The fix was to disconnect the battery overnight to lose the semi-volatile memory in the ECU. This was only discovered because Camaro owners like to put there cars on a dyno, and the variation in power between cars was huge... it seems some dealers put low octane in the car when new to save money on the 'free' full tank!!

[SpykerOwner]

That's an interesting and worrying combination.

[F Spider]

As long as you do not have to get a state inspection, it seems to be good to use the masterswitch once in a while.